Polyphasic study of microbial communities of two Spanish farmhouse goatsʹ milk cheeses from Sierra de Aracena Original Research Article

The microbial communities present in 2 different types of farmhouse goatsʹ milk cheese from the Aracena mountains (southwest Spain), Quesailla Arochena (hard cheese) and Torta Arochena (soft cheese), have been studied using both culture-dependent and culture-independent techniques. All bacterial isolates were clustered by using randomly amplified polymorphic DNA (RAPD) and identified by 16S rRNA gene sequencing, species-specific PCR and multiplex PCR. Thus a total of 26 different species were identified, the majority belonging to the lactic-acid bacteria (LAB), mainly represented by Lactococcus lactis and Lactobacillus species such as Lactobacillus plantarum and Lactobacillus paracasei, together with a significant proportion of enterococci. Amongst the non-lactic-acid bacteria (NLAB), which represented 37% of the isolates in Torta Arochena, enterobacteria were the most important, Hafnia alvei and Serratia liquefaciens being the predominant species in Quesailla Arochena and Torta Arochena respectively. Moreover, RAPD analysis of the isolates revealed that most of the genotypes were specific to one of the cheeses, although a few genotypes common to both cheeses were found.